Undetachable drawer rail

ABSTRACT

A undetachable drawer rail includes a U-shaped outer track ( 10 ), a U-shaped inner track ( 20 ), a bearing race ( 30 ), a rail ( 40 ) slidably mounted on the inner track ( 20 ), a resilient latch ( 50 ) secured on the rail ( 40 ) and a intermediate stop ( 60 ). The inner track ( 20 ) has a limit block ( 21 ) with a passage attached to the front end. The resilient latch ( 50 ) with a V-shaped fork ( 52 ) passes through the passage in the limit block ( 21 ) by compressing the fork ( 52 ), and then the fork ( 52 ) returns to its original shape after entering the inner track ( 20 ). Thereby, the rail ( 40 ) is blocked. Additionally, the outer track ( 10 ) further has an inner arrow shaped stub ( 13 ) formed toward the inner track ( 20 ) to selectively abut the intermediate stop ( 60 ) to enhance stability of the undetachable drawer rail.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a drawer rail, and particularly to a rail for an undetachable drawer that is easily assembled and is not easily damaged when assembled.

[0003] 2. Description of Related Art

[0004] Drawer rails are normally used with drawers or keyboard racks of computer desks and are mounted on sides of the drawers or other retractable fixtures to mount them in a desk or the like. Two types of drawer rails are available, detachable drawer rails that allow drawers to be removed from desks and undetachable drawer rails that do not allow drawers to be removed.

[0005] With reference to FIG. 8, a first kind of conventional undetachable drawer rail is composed of a U-shaped outer track (70) with a closed end (72) and an open end (not numbered), a U-shaped inner track (700) and a rail (74).

[0006] The U-shaped inner track (700) is slidably mounted inside the U-shaped outer track (70) in the same opening direction as the U-shaped outer track (70). The U-shaped inner track (700) has two ends, two sidewalls, a limit tab (not numbered) and a limit block (73). The limit tab (not numbered) is mounted on the end of the U-shaped inner track (700) abutting to the close end (72) of the outer track (70). The limit block (73) is attached to the other end of the U-shaped inner track (700) near the open end of the outer track (70). Additionally, a ball bearing race (71) is slidably mounted between the inner track (700) and the rail (74) to make the rail (74) slide more easily in the inner track (700). Ball bearings (not numbered) in the ball bearing race (71) are located on both sidewalls of the U-shaped inner track (700). The rail (74) is a U-shaped frame with a bottom (not numbered), two inward curved sidewalls, an open end (not numbered) and a closed end (not numbered) and is adapted to be attached to a side of a drawer. A flange (741) is formed in a middle portion of the rail (74) and protrudes toward the inner track (700).

[0007] With further reference to FIG. 9, the rail (74) is installed in the inner track (700) by inclining the rail (74) relative to the inner track (700) so that the flange (741) on the rail (74) can move past the limit block (73) at the end of the inner track (700). With the rail (74) inclined, the open end of the rail (74) is inserted into the ball bearing race (71) and the ball bearings are guided into the curved sidewalls. When the flange (741) is past the limit block (73), the rail (74) must be pressed forcibly completely inside the inner track (700). After the rail (74) has been installed in the inner track (700), the rail (74) cannot be separated from the inner track (700) again. During the installation of the rail (74), the rail (74) is easily deformed and damaged.

[0008] With reference to FIG. 10, a second type of conventional undetachable drawer rail is composed of a U-shaped outer track (80), a U-shaped inner track (800) and a rail (84). The structure of the second conventional undetachable drawer rail and the engaging means are the same as the first type, except the inner track (800) has a limit block (83) that is a different shape and the rail (84) has a flange (841) with a different shape and orientation. With further reference to FIG. 11, the rail (84) is also easily deformed and damaged since assembling the second type of undetachable drawer rail requires that the rail (84) be pushed forcibly into the inner track (800).

[0009] To overcome the shortcomings of these two conventional undetachable drawer rails, the present invention provides an undetachable drawer rail to mitigate and obviate the aforementioned problems.

SUMMARY OF THE INVENTION

[0010] The main objective of the invention is to provide an udetachable drawer rail that can be assembled without deforming and damaging elements of the drawer rail and has an excellent positioning capability.

[0011] Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is an exploded perspective view of an undetachable drawer rail in accordance with the present invention;

[0013]FIG. 2 is a partially exploded perspective view of the undetachable drawer rail in FIG. 1;

[0014]FIG. 3 is an enlarged cross-sectional top plan view of the undetachable drawer rail in FIG. 1 being assembled;

[0015]FIG. 4 is an enlarged side plan view in partial section of the undetachable drawer rail in FIG. 1 where a resilient latch is blocked by two locking protrusions of a limit block;

[0016]FIG. 5 is an enlarged side plan view in partial section of the undetachable drawer rail in FIG. 1 where an intermediate stop gravitates to a inclined position to abut an inner arrow-shaped stub;

[0017]FIG. 6 is an enlarged side plan view in partial section of the undetachable drawer rail in FIG. 5 when the intermediate stop is supported in a horizontal position to allow the inner track to pass the inner arrow-shaped stub;

[0018]FIG. 7 is an enlarged side plan view in partial section of another embodiment of the resilient latch engaging the limit block in accordance with the present invention;

[0019]FIG. 8 is a partially exploded perspective view of a first conventional undetachable drawer rail in accordance with the prior art;

[0020]FIG. 9 is a cross-sectional top plan view of the first conventional undetachable drawer rail in FIG. 8 during assembly;

[0021]FIG. 10 is a partially exploded perspective view of a second conventional undetachable drawer rail in accordance with the prior art; and

[0022]FIG. 11 is a cross-sectional top plan view of the second conventional undetachable drawer rail in FIG. 10 during assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0023] With reference to FIGS. 1 and 2, an undetachable drawer rail in accordance with the present invention is composed of a U-shaped outer track (10), a U-shaped inner track (20), a bearing race (30), a rail (40), a resilient latch (50) and an intermediate stop (60).

[0024] The U-shaped outer track (10) is adapted to attach to an inner side face of a drawer compartment in furniture and has a front end (not numbered), a rear end (not numbered), a vertical base (not numbered) and two sidewalls (not numbered). The vertical base has a top edge (not numbered) and a bottom edge (not numbered). The sidewalls respectively extend perpendicular from opposite edges of the vertical base. A guide (11) is defined in each sidewall of the outer track (10). An inner arrow-shaped stub (13) is formed on the vertical base of the outer track (10).

[0025] The U-shaped inner track (20) has a configuration similar to the outer track (10) with a front end (not numbered), a rear end (not numbered), a vertical base (not numbered) and two sidewalls (not numbered) and is slidably mounted inside the U-shaped outer track (10). The vertical base has a top edge (not numbered) and a bottom edge (not numbered). The sidewalls are S-shaped and respectively extend perpendicular from opposite edges of the vertical base. The intermediate stop (60) is pivotally mounted on the vertical base near the rear end of the outer track (10), and a limit block (21) is attached to the front end of the outer track (10). The limit block (21) is U-shaped, has a vertical base (not numbered), two sidewalls (not numbered) and two locking protrusions (212) and is made of resilient material such as rubber. The sidewalls of the limit block (21) correspond to the sidewalls of the inner track (20). The locking protrusions (212) are formed perpendicular to the limit block (21) respectively on opposite sidewalls of the limit block (21) to form a passage (213) between the two locking protrusions and two sub-passages (210) between the sidewalls and the corresponding locking protrusions. Additionally, an opening (23) is defined in the vertical base near the rear end of the inner track (20).

[0026] The ball bearing race (30) is substantially U-shaped and movably mounted between inner faces of the sidewalls of the inner track (20) to allow the rail (40) to slide fluidly with the inner track (20).

[0027] The rail (40) is adapted to be attached to a side of a drawer and has a rear end (41), a front end (42) and a tongue (43) defined in a middle portion of the rail (20). The rear end (41) is open, and the front end (42) is closed.

[0028] The resilient latch (50) is V-shaped and has a front end (not numbered), a rear end (not numbered), a fork (52) and a proximal head (5 1). The fork (52) is formed on the front end of the resilient latch (50) and has two tines (not numbered), and the proximal head (51) is formed at the rear end of the resilient latch (50). The fork (52) extends toward the front end (42) of the rail (40), and each tine of the fork (52) has a distal end (not numbered), a proximal end (not numbered) and a flat face (not numbered) formed on the distal end. A vertical slot (511) corresponding to the tongue (43) on the rail (40) is defined in the proximal head (51) of the resilient latch (50) to attach the resilient latch (50) to the rail (40) by wedging the tongue (43) into the vertical slot (511).

[0029] The intermediate stop (60) selectively stops the inner track (20) from moving into the outer track (10) until the rail (40) has moved completely into the inner track (20). The intermediate stop (60) is a strip with a distal end (61), a proximal end (not numbered) and two longitudinal edges and has a pair of stop wings (610) and a pair of inclined guide wings (612). The proximal end of the intermediate stop (60) is pivotally attached to the vertical base of the inner track (20) and the distal end (61) extends toward the rear end of the inner track (20). The stop wings (610) are formed on opposite edges of the intermediate stop (60) at the distal end (61) perpendicular to the strip and extend through the opening (23) in the inner track (20) to align with the inner arrow-shaped stub (13) on the outer track (10). The inclined guide wings (612) are formed on opposite edges of the intermediate stop (60), protrude toward to the rail (40) and diverge as they approach the distal end (61) to linearly connect with the parallel stop wings (610).

[0030] With further reference to FIG. 3, the rear end (41) of the rail (40) passes through the limit block (21) via the sub-passages (210) and the passage (213) when the rail (40) is installed in the inner track (20). Sidewalls of the rail (40) pass through the sub-passages (210) between the inner rail (20) and the locking protrusions (212), and the passage (213) allows the resilient latch (50) and the tongue (43) to pass through the limit block (213). With further reference to FIG. 4, the proximal head (51) pass through the passage (213) first, and the fork (52) having a larger width than the passage is slightly compressed as it passes through the passage (213). When the fork (52) completely passes through the limit block (21), the fork (52) extends to its original size, and the flat faces at the distal ends of the tines press against the locking protrusions (213) when the drawer is pulled out. Thereby, the rail (40) is kept from detaching from the inner track (20). Moreover, since the rail (40) is installed in the inner track (20) through the front end of the inner track (20) rather than being pressed into the inner track (20) as with the conventional undetachable drawer rail, the rail (40) is not damaged or deformed when the undetachable drawer rail is assembled. When the drawer is pulled out, the rail (40) pulls out of the inner track (20) until the resilient latch (50) abuts the limit block (21).

[0031] With further reference to FIG. 5, then the inner track (20) is drawn out of the outer track (10), and the stop wings (610) pass on either side of the arrow-shaped stub (13). When the stop wings (610) pass the arrow-shaped stub (13), the distal end (61) of the intermediate stop (60) gravitates down to an inclined position such that the stop wings (610) will abut the arrow-shaped stub (13) when the inner track (20) is pushed into the outer track (10). Thereby, both the inner track (20) and the rail (40) support the drawer when the drawer is pulled out, and the drawer and the rail (40) are held more securely and stably.

[0032] With further reference to FIG. 6, when the drawer is pushed back, the rail (40) moves inward and the rear end of the rail (40) lifts up the dropped distal end (61) of the intermediate stop (60) to a horizontal position. Thereby, the stop wings (610) of the intermediate stop (60) can pass by the arrow-shaped stub (13) and allow the inner track (20) to move into the outer track (10) and the drawer compartment.

[0033] With reference to FIG. 7, another embodiment of the resilient latch (50′) has a guide head (521′) with an arc root formed at a distal end of each tine of the fork (52′) forming a detent (53′) between the guide head (521′) and the proximal head (51′). When the drawer is pulled out, the guide heads (521′) pass through the passage (213) between the locking protrusions (212) and hold the locking protrusions (212) inside the detent (53′) to enhance the stability and positioning capability of the undetachable drawer rail. When the drawer is pushed back into the drawer compartment, the force of pushing the rail (40) releases the locking protrusions (212) from the detents (53′).

[0034] Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. 

What is claimed is:
 1. A undetachable drawer rail comprising: a U-shaped outer track (10) adapted to attach to an inner side face of a drawer compartment; a U-shaped inner track (20) with a bottom, a front end, and a rear end, the inner track (20) slidably mounted inside the U-shaped outer track (10) and having a limit block (21) mounted in the front end of the inner track (20) and a intermediate stop (60) mounted near the rear end, wherein the limit block (21) is U-shaped with a vertical base, two sidewalls corresponding to the inner track (20) and two locking protrusions (212) formed perpendicular to the limit block (21) and respectively on opposite sides of the limit block (21) to form a passage (213) between the two locking protrusions (212) and two sub-passage (210) between the sidewalls and the corresponding locking protrusions (212); a ball bearing race (30) movably mounted on the inner track (20); a rail (40) adapted to attach to a side of a drawer and slidably mounted in the inner track (20); and a resilient latch (50) having a front end, a rear end, a V-shaped fork (52) with two tines formed at the front end and a proximal head (51) formed at the rear end, wherein the fork (52) extends toward the front end of the inner track (20) and each tine of the fork (52) is adapted to abut the locking protrusions (212) of the limit block (21).
 2. The undetachable drawer rail as claimed in claim 1, wherein the U-shaped outer track (10) further has an inner arrow-shaped stub (13) formed on the outer track (10); the U-shaped inner track (20) further has an opening (23) defined in the other end opposite to the limit block (21); and the intermediate stop (60) is a strip and has a proximal end, a distal end (61) pivotally attached to the inner track (20), a pair of stop wings (610) formed in parallel at the distal end (61) and extending through the opening (23) in the inner track (20) and a pair of inclined guide wings (612) extending toward the rail (40) and diverging toward the distal end (61) to linearly connect with the pair of stop wings (610), wherein the pair of stop wings (610) aligns with the inner arrow-shaped stub (13) on the outer track (10).
 3. The undetachable drawer rail as claimed in claim 1, wherein the rail (20) further has a open rear end (41) and a tongue (43) defined in a middle portion; and the resilient latch (50) further has a vertical slot (511) corresponding to the tongue (43) on the rail (40) defined in the proximal head (51) of the resilient latch (50).
 4. The undetachable drawer rail as claimed in claim 2, wherein the rail (40) further has a open rear end (41) and a tongue (43) defined in a middle portion; and the resilient latch (50) further has a vertical slot (511) corresponding to the tongue (43) on the rail (40) defined in the proximal head (51) of the resilient latch (50).
 5. The undetachable drawer rail as claimed in claim 1, wherein each tine of the fork (52) has a flat face formed at a distal end to abut the corresponding locking protrusions (212).
 6. The undetachable drawer rail as claimed in claim 2, wherein each tine of the fork (52) has a flat face formed at a distal end to abut the corresponding locking protrusions (212).
 7. The undetachable drawer rail as claimed in claim 4, wherein each tine of the fork (52) has a flat face formed at a distal end to abut the corresponding locking protrusions (212).
 8. The undetachable drawer rail as claimed in claim 1, wherein each tine of the fork (52′) has a guide head (521′) with an arc root formed at a distal end and a detent (53′) formed between the guided head (521′) and the proximal head (51′).
 9. The undetachable drawer rail as claimed in claim 2, wherein each tine of the fork (52′) has a guide head (521′) with an arc root formed at a distal end and a detent (53′) formed between the guided head (521′) and the proximal head (51′).
 10. The undetachable drawer rail as claimed in claim 4, wherein each tine of the fork (52′) has a guide head (521′) with an arc root formed at a distal end and a detent (53′) formed between the guide head (521′) and the proximal head (51′). 